Last year, 16,364 babies were born to a parent or caregiver on a benefit – mostly the DPB.

Almost half of those caregivers were Maori, figures provided under the Official Information Act show.

In 2010, some 4800 births were second, or subsequent, children being added to an existing DPB, which happens most commonly in Whangerei, Whakatane, Rotorua, Kawerau and Wairoa.

"The high rate of children born on to welfare gives rise to numerous health and social problems down the line, not least abuse and neglect," Ms Mitchell writes in today's print edition of the National Business Review.

It is an irresponsible society which sanctions having babies on benefits as part of its culture, she says.

Time-limiting benefits, as they do in the United States, closes existing loopholes which restart the clock when another baby is born.

"That regime unequivocally puts the responsibility firmly on the parent to limit their family size without totally dumping a safety net.

"Knowingly bringing children into the world with no ability to raise them independently is hard to justify at any level."

Given the recent focus on affordable housing, there will also be interest in the marketing of a 60ha site at Flat Bush, on the fringe of Auckland's urban boundaries, which may eventually be used for high-density, small dwellings.